Question: Simplify the expression. $(-5z-1)(-4z-8)$
Solution: First distribute the ${-5z-1}$ onto the ${-4z}$ and ${-8}$ $ = {-4z}({-5z-1}) + {-8}({-5z-1})$ Then distribute the ${-4z}.$ $ = ({-4z} \times {-5z}) + ({-4z} \times {-1}) + {-8}({-5z-1})$ $ = 20z^{2} + 4z + {-8}({-5z-1})$ Then distribute the ${-8}$ $ = 20z^{2} + 4z + ({-8} \times {-5z}) + ({-8} \times {-1})$ $ = 20z^{2} + 4z + 40z + 8$ Finally, combine the $x$ terms. $ = 20z^{2} + 44z + 8$